Tertiary alkoxy amino silanes



Patented Sept. 4, 1951 UNITED STATES PATENT OFFICE TERTIARY ALKOXY AMINO SILANES No, Drawing. Application April 22, 1946, Serial No. 663,946

1'5Claims. 1

This application is a continuation-in-part of our copending application. Serial No. 470,904, filed December 31, 1942.

The present invention relates to novel organic compounds of silicon. cerns organic compounds-of silicon containing a hydrolyzable group, especially such as an amino or nitrogen group, and having one'or more other groups which are resistant to hydrolysis, especially a tertiary-alkoxygroup or otheranalogous tertiary .carbinoxy group; also ,hydrolyzation products and otherderivatives of the foregoing have been invented by us. Di tertiary-butoxydiaminosilan'e,

is an example of the novel compoundsa-nd products of our invention, though we have produced, and here contemplate, a number of other compounds or products having many of the same novel attributes and properties, as will be discussed more fully hereinafter. Various unique uses of these novel products will also be mentioned later herein.

Silicon tetrachloride SiClr, is a material which has been known for'many, many years. It-can he produced relatively cheaply in difierent ways,

as for example, by blowing chlorine through a tower packed with sand coke, maintained under controlled temperature andv other conditions. Thus it will be seen that silicon tetrachloride can be made from relatively cheap raw materials. Heretofore others have produced certain organic silicon compounds employing silicon tetrachloride as a reactant. One of the best known of these is ethyl orthosilicate, i. e. (CzI-I50)4Si, which may also be referred to as tetraethoxysiland (Heretofore the term silicane has frequently been used in connection with this class of compounds, but"silane is preferred in the more modern nomenclature). It will be noted that ethyl orthosilicate, i. e. tetra-ethoxysilane (known as early as the year 1846), is made up of primary alkoxy groups joined to'the silicon atom. This product can be produced by the reaction of silicon tetrachloride withethyl alcohol under certain conditions. Ethyl alcohol is of course a primary alcoh Land the ethoxy radical of that alcohol will replace the chlorine of silicon tetrachloride, thus giving a tetraethoxysilane, which is more commonly known as ethyl orthosilicate. I-ICl is evolved in such reaction. The ethyl orthosilicate, however, if exposed tomoist More particularly itconatmosphere hydrolyzes ,ina short time, apparently reproducing the ethyl alcohol, which vola- .tilizes, leaving a residue of silica.

Also, heretofore ether alkoxy silanes of-primary alcohols, and, to a lesser extent, of secondary alcohols, have been produced. In connection with the difficulties encountered in the production of alkoxy silanes of secondaryalcohols, see Alkyl ()rthosilicates by A. W. Dearing and E.;Emmet Reid, Journal American Chemical Society, vol. 50, (1928), page 3058. None ofsuch prior artalkoxy silanes, however, have hadthe properties or characteristics of the products of our invention, herein described and claimed, and none of the products of our invention hereinafter described and illustrated have previously been known. 6

The subject matter herein described an claimed is in the nature of an amplification of subject matter taken directly from our prior application Serial No. 470,904, filed December 31, 1942, and is most particularly concerned with compounds which are silicon derivatives of tertiary alcohols and whichialso contain reactive or readily hydrolyzable radicals; and this application isespec-ially concerned with products of that type which, following hydrolysis, yield a nonacidic reaction product.

The tertiary alcohols may contain such groups as alkyl, chloroalkyl, aryl, aralkyl, or alicyclic groups attached to the ,carbinol carbon, and the term tertiary-carbinoxy .as hereinused is intended to cover the radical derived .from any tertiary alcohol by removal of the hydrogen atom from the hydroxyl group attached to the tertiary carbon atom. Analogously, the term carbinoxy covers the radicalderived from any alcohol by removal of the hydrogen atom from the hydroxyl (alcohol) group.

Tertiary-carbinoxy .aminosilanes, of which a number of examples are given hereinafter, are products of the type above identified and are unique and different, to the bestof our knowledge, from any products known prior to our invention. These products are widely different in stability and other properties from the'prior-art alkoxy silanesabove mentioned, e. g. ethyl orthosilicate, and they have some very important differences even from certain other tertiary-carbinoxy silanes, e. g. tertiary-alkoxy chlorosilanes or other tertiary-carbinoxy chlorosilanes, disclosed for the first time, insofar aswe are aware, in our aforesaid parent application Ser. No. 470,904. l g 5 The tertiary-carbinoxy chlorosilanes, upon coming in contact with, for example, cloth or paper, will react with the adsorbed moisture in the material and perhaps also with the hydroXyl groups of the cellulose to eliminate chlorine from the molecule in the form of hydrogen chloride. This strongly acid reaction product will cause serious degradation of the cloth or paper under ordinary conditions. However, the tertiary alkoxy aminosilanes, particularly comprehended herein,. when similarly coated on cloth and exposed to similar conditions, will produce ammonia or other nitrogen-containing compound (which is not harmful to cloth or the like) and leave a treatment on the fabric which is highly resistant to further hydrolysis or reaction under ordinary conditions. Such a treatment serves to produce a new type of fabric (further described and claimed in the copending application of Carl Shelley Miner, Jr., Ser. No. 663,947, filed concurrently herewith) which is repellent to water and will withstand washing in water or dry-cleaning solvents, such as ordinary cleaning naphtha. I V

The salient chemical compounds illustrative of our invention herein described and claimed have, or approximate, the molecular formula (RO)eSiX4-1, whereRO represents an alkoxy or other carbinoxy group and at least one BO represents a monovalent tertiary-carbinoxy radical, X represents a monovalent amino or nitrogen group and a: is an integer from 2 to 3. Certain outstanding compounds of our invention, coming within the aforesaid classification, of which ditertiary-butoxydiaminosilane and di-tertiaryamoxydiaminosilane are examples, are liquid products under ordinary conditions, viz. ordinary room temperatures and pressures. Other products of our invention, of the type indicated, may have appreciably higher or lower meltin and/or boiling points depending upon the particular substituent groups employed.

Further details in respect to various of the compounds of our invention will appear in connection with. the description of illustrative methods for preparing the same.

Further, our invention comprehends chemical compounds having the formula XI Ro-si-X XII where R is a tertiary-carbinoxy group, X is a monovalent hydrolyzable nitrogen group, and X and X" are monovalent groups, e. g. organic groups or hydrolyzable nitrogen groups, and may be thesame or different. Other variations are discussed and illustrated hereinafter.

Organic silicon compounds of this invention which contain hydrolyzable nitrogen attached to silicon may preferably be prepared by amination or ammonolysis, e. g. with anhydrous ammonia, of tertiary-carbinoxy chlorosilanes. The chlorosilanes may in turn be prepared by reaction of tertiary alcoholswith silicon tetrachloride in the presence of an acid acceptor, as described and claimed in our said .copending application Ser. No. 470,904. While organic chlorine-silicon compounds are particularly illustrated herein as the intermediate compounds, compounds containing a halogen other than chlorine, for example, bromine, are also contemplated.

Ammonia may be reacted with the various tertiary-corbinoxy chlorosilanes with complete elimination of the chlorine atoms attached to silicon. While this ammonolysis reaction presumably initially results in a simple replacement of chlorine by amino groups, and while the resulting organic silicon products do contain hy drolyzable nitrogen, the proportion of such nitrogen as determined by analysis may be somewhat less than the theoretical amount based on the substitution of NH2 for -C1 in the original tertiary-carbinoxy chlorosilane. In many cases, however, the percentage of hydrolyzable nitrogen closel coincides with the theoretical amount, justifying the naming of these two compounds as tertiary-carbinoxy aminosilanes.

Thus, compounds have been isolated which on analysis have been found to agree closely with the formula (ROMSiXr-e above discussed, wheres is 2 or 3. Also and in other words, compounds have been isolated which on analysis have been found to agree closely with the above-mentioned formula II but in which X represents a te'rtiary-carbinoxy group, X" represents a tertiary-carbinoxy or an amino roup, X is specifically an amino group, and R0 is specifically a tertiary-alkoxy group. Of these, the preferred compounds for certain present uses are di-tertiary-carbinoxy diaminosilanes, e. g. the di-t-alkoxy diamino silanes,

in which the two monovalent tertiary-alkoxy radicals may be the same or difierent, and likewise the amino (or nitrogen) groups may be the same or different; and, as the term amino group is used herein, it may refer to a group derived from ammonia, from an amine or from an equivalent amino compound. 7

In all cases investigated, even including resinous and apparently partially condensed products, e. g. products obtained from the ammonolysis of the t-alkoxy trichlorosilanes, the compounds prepared by ammonolysis as above indicated contain hydrolyzable nitrogen and are capable of rendering acid-sensitive hydrophilic materials (e.- g. cellulose) water-repellent without degradation of the substance; and the water-repellency of cloth or the like, thus treated, effectively with stands the washing thereof in water or hydrocarbon solvents.

The term hydrolyzable nitrogen as here used refers to nitrogen which is liberated either in the form of ammonia, an amine or an equivalent amino compound or salt on hydrolysis. Thus, the nitrogen may be present in the organic silicon material in such groupings as Illustrative and advantageous procedures for preparing the new class of compounds of this invention will now be given. However, it will be understood that the novel products are contemplated irrespective of the particular method of production described. In the following examples, all parts are by weight (unless the contrary is stated).

EXAMPLE I Preparation of di-t-butomydiaminosilane One thousand and fifty (1050) parts of bengene and 510 parts of silicon tetrachlorideare placed in a reaction vessel, preferably glass lined,

and :cooled to about HP :6. rbyxrneanswnf lbrine-or other theatexchange medium. Ti lihilez stirring the solution, 4.98 partsunipyridine' is :slowly added, the temperature: being kept below 20 .C. during the addition. The addition f thecpyridineurequiresa substantial period of'tirne, e; g. from' l to 2 hours, more or less, depending-on-the-efiiciency of the cooling system. Throughout the entire addition the pyridine and silicon tetrachloride react to iorrna white precipitate which toward the end forms a fairly thick paste with the "benzene. The formation of a similar white precipitate on the walls-of the reaction vessel as a result of the inter-reaction of the -vap'o'rs' of the'reactants can be reduced to a minimum by having the pyridine inlet extend 'to within a few inches of the surface of th'e'benzene. Afterad dition of the pyridine is 'completethe' mixture' is stirred, e. g. an additional 15 minutes, :more or less.

Four hundred and forty-four (444) parts of tertiary mm alcohol :is then "added, .all'sat once. The "temperature rises slowly at first, but once above about 30 C. it rises rather quickly. Unless the dimensions of the reaction vessel are sufficiently restricted, it desirable to employ internal cooling coils or elements, so that loss of material due to overheating will be avoided. It has beenfound convenient to allow the temperature to rise to about 40-45 (3;; then, by controlled cooling, it is kept at this temperature until the reaction subsides. This requires-about 1% to 2 hours, more or less. The mixture isthenheated slowly over 'a period of abouti5 minutesto reflux temperature. The slow heatingten'ds to form a granular pyridinehydroclll'oride which lends 'itself well to subsequent filtration. Refluxing is then continued for about "two hours, to insure completion of the reaction. Itis then cooled and filtered to remove the pyridine hydrochloride, recovering both the filtrate and filter cake. What is ordinarily a very slow filtration can be accomplished quickly by forming a'bed of a filteraid such as Filter Cel or Super oer on a filtering mediumsuch as cloth. This can be done by suspending --20- parts of the filter-aid in 200-300 parts of benzene and filtering this suspension through the filtering apparatus. The 'benzenecan be'used later iforwashing purposes. The pyridinehydrochloride is substantially freed of filtrate and then washed with benzene until substantially free of the di-tertiary-butoxydichlorosilane' product.

The filtrate and washings are coinbined'and'the benzene is distilled oii at atxnospheric pressure. When there is no further benzene distillate, the product iscooled-and the distillation continued at reduced pressure, engu-an absolute pressure of 10 to 100mm,, to separate the di-tertiary-butoxydichlorosilane product from remaining materials (i. e..products of side reactions, impurities, etc). The product tends to decompose when distilled at atmospheric pressure. A glass lined still, suitable for vacuum distillation, may be employed for both the distillation. at atmosphericpres'sure and the subsequent distillation at reduced-pressures.

After a small amoimt of low boiling material (mostly benzene) .is removed. in the vacuum .distillation, the major portion of the product boils at 66 C. at -11 mm'absolute pressure. The distillate is sometimes cloudy with pyridine hydrochloride, butthis settles out on standingtand has proved tobe of. noconsequence when the product is .usedin otherlreact'ion-s. About 630 parts by weight (85% of theoretical yield) of iii-tert- 6 butoxydichlorosilane is obtained. This is then here used by us asandntermediate product, from which awe make ,aminosilanes, as herein described and claimed.

'In one instance anhydrous ammonia was bubbled into .a cooled solution of 2i.5 grams of the .di-t-butoxydichlorosilane in 11-50 cc. of benzene. The mixture "was filtered and the filtrate distilledyielding 1.6.grams(78% yield) oia liquid product boiling at Bil- 'C. at 30 mmqwhich was shown by analysis to correspond closely :to the theoretical chemical formula of di t-butoxydiaminosilane. (A small amount of a viscous liquid. polymeric residueremained after the distillation; this residue was shown on analysis to contain both silicon .and nitrogen.) Increasing the rate of. addition of. the anhydrous ammonia improved the yield of the desired product.

A somewhat improved method of preparation involves the use of liquid-ammonia in .a pressure vessel. For example, under proper temperature and other conditions liquid ammonia may be poured into .an open vessel onto the chlorosilane asla separate layer; the vessel closed, and the reaction initiated by agitation and mixing oi the two liquids. Another method, employed commercially, involves forcing liquid ammonia into the closed reaction vessel containing the t butoxy chlorosilane. (If the reaction vessel is notkept under substantial superatmospheric pressure, the ammonia will, of course, be in the form of a gas therein, rather than ali'quidL) Iniafspecificexample, amixture of 151.1 parts heptane, 50.0 parts pure di-t-butoxydichlorosilane and 20.7 parts liquid ammonia was made up in a pressure vessel, andheld under pressure and with occasionalagitation for 30 minutes. At the end of this periodexcess ammonia was carefully released, and the product was removed from the pressure reaction vessel. Ammonium chloride was then removed from the product by filtration, and the heptane was removed therefrom by vacuum distillation with a maximum temperature (if-45 C. The remaining liquid was distilled under vacuum and yielded 83.6% by weightlof the theoretical maximum yield of dit-butoxydiaminosilane. lihe amino silane producthadfa boilingpointof 81 C. at a pressure of 15.mm.,.and showed-an analysisof 13.48% .Siand 13.7% N (theoretical 13.55% Si and 13.55% N).

EXAMPLE 11 Preparation of cZi-t-amowydiaminosilane In amanner similarto that of Example I, di-t- .amoxydiaminosilane may be prepared from anhydrous ammonia and ,di-t-amoxydichlorosilane.

In the preparation of di-tertiary-amoxydichloro=- silane-the process is substantially identical with thatdescribedin Example Iior di-tert-butoxydi .chlorosilane, except that 528 parts by weight (6.0

mols) of tertiary-amyl alcohol are used in place of the 444 parts of tertiary-butyl alcohol above indicated. The boiling pointof the di-tertiaryamoxydichlorosilane is C. at 22 mm pressure. Di-tertiary-amoxydiaminosilane boils at about 118 C. at 20mm. pressure.

EXAMPLEIII Preparation of other di-t-carbinory ,diaminosilanes .Inamanner similar'tothat of ExamplesjI and II, .bis(tertsdichlorobutoxy)'dichlorosilane, B. P.

chlorosilane, B. P. 170-3 C. at mm'.;' bis(dihydroterpineoxy)dichlorosilane, B. 1?. 195 C. at7 mm.; and diterpineoxyand dilinalooxy-dichlorosilanes (which latter two compounds could not be distilled without decomposition at 5 mm. pressure) were converted to the correspondlng'di-tcarbinoxy diaminosilanes by reaction with anhydrous ammonia. The dichloro compounds were prepared by reaction of silicon tetrachloride, in the presence of an acid acceptor such as pyridine, with dichloro-tcrt-butyl alcohol, 1-ethylcyclohexanol, dihydroterpineol, terpineol and linalool, respectively.

7 EXAMPLE IV Preparation of tri-t-butoryaminosilarie A solution of 98.0 parts of di-tert-butoxyclichlorosilane, 31.6 parts of pyridine and 75 parts of tert-butyl alcohol was allowed to stand in a closed container for 72 hours or until the precipitation of pyridine hydrochloride ceased. The mixture was then filtered, the precipitate washed with benzene, and the filtrate fractionally distilled. Tritert-butoxychlorosilane (55 parts) was collected at 76 C. at 7 mm. pressure.

A mixture of 50 parts (0.177 mol) of the tri-t butoxychlorosilane and 80 parts of liquid am= monia was then allowed to stand at room tem= perature until the excess ammonia had evaporated. The reaction proceeded rapidly, aided by occasional agitation. The reaction mixture was heated to remove the last traces of ammonia. The liquid was removed from the ammonium chloride, the latter rinsed with petroleum ether, and the washings added to the liquid. After removal of the petroleum ether, distillation at reduced pressure was carried out. There was obtained 39.8 parts or" tri-t-butoxyaminosilane boiling at 825 C. at a pressure of 10-11 mm., cor responding to an 87.4% yield.

EXAMPLE V Preparation of dimethoaty-t-butoa:yaminosilane Forty grams (1.25 mols) of methanol was reacted with 208 grams (1 mol) of t-butoxytrichlorosilane (which latter may be prepared in the manner hereinafter described in Example VIII) in the presence of 105 grams of pyridine; there was obtained 144 grams of a fuming liquid product boiling at 75-80 C. at 75 mm. and consisting primarily of a mixture of methoxy-tbutoxychlorosilanes. Of this mixture, a 45 gram portion was added to 100 grams of liquid ammonia at dry ice temperature, i. e. at the temperature of solid carbon dioxide. After comple tion of the reaction the excess ammonia was allowed to boil off, ether was added to replace the excess ammonia as a vehicle for the batch, the same was then filtered and the ether removed at reduced pressure. The remaining liquid was distilled under vacuum. A fraction was obtained, boiling at -80-90 C. at 50 mm. pressure, which was shown by analysis to correspond closely to the theoretical formula of dimethoxy-t-butoxy aminosilane. 1

EXAMPLE VI Preparation of alkyl t-alkoacy aminosilanes Amino compounds containing alkyl or aryl groups in addition to tertiary-carbinoxy groups may be prepared, for example, from alkyl or aryl polychlorosilanes obtained, for example, by means of the known Grignard reaction. Thus,

ethyl trichlorosilane may be reacted with .tertiary butyl alcohol in the presence of alpha-picoline, and the product further reacted with anhydrous ammonia, to yield ethyl-t-butoxyaminosilanes,

e. g. ethyl-di-t-butoxyaminosilane, or ethyl-tbutoxydiaminosilane, depending upon the proportion of reactants.

EXAMPLE VII Preparation of n-batoxy di-t-butoxyamz'nosz'lane A mixture of 7.4 parts of n-butyl alcohol and 20.6 parts of di-t-butoxydiaminosilane which was made according to Example I, was lowly heated to 100-110 C. and held at that temperature range for one-half hour. During the initial heating, ammonia was evolved. The resulting mixture was fractionated and a portion recovered, boiling at 113.5 C. at 15 mm. and corresponding closely to n-butoxy-di-t-butoxyamin silane.

Similarly, compounds were prepared in which methyl and isopropyl groups replaced the n-butyl groups.

EXAMPLE VIII Ammonolysis of t-butoxytrichlorosz'lane The intermediate chloro compound was prepared by the slow addition of a mixture of 37 parts (0.5 mol) of tertiary-butyl alcohol and 39.5 parts (0.5 mol) of pyridine to a solution of 200 cc. of petroleum ether (boiling range 35-60 C.) and 85 parts (0.5 mol) of silicon tetrachloride, cooled to about 17 C. The mixture was kept at this temperature during the addition which required five (5) hours and then it was heated to 30 C. over a four (4) hour period. The reaction mixture stood overnight and was then stirred for five (5) hours at 30 C., filtered and the product distilled; Seventy-one and onehalf parts (0.39 mol) of tertiary-butoxytrichlorosilane (B. P. C. at 87 mm.) was obtained, representing a yield of 69% of the theoretical.

This compound was treated with an exces of liquid ammonia under superatmospheric pressure. A soft resinous product was obtained which was soluble in benzene and contained hydrolyzable nitrogen. On standing, the resin gradually hardened, with evolution of ammonia and reduction in solubility. Analysis of this product as t-butoxytriaminosilane was inhibited because of the tendency of the compound to lose ammonia. However the product as made contains hydrolyzable nitrogen.

EXAMPLE IX Tert butomy tert monochlorobutoxydzamz'nosilane is 25.4% active chlorine.

Liquid ammonia was reacted with the tertbutoxy tert monochlorobutoxydichlorosilane in ether solution at -78 C. The reaction pro- 9 ceededrapidly at this temperature. The purified product gave the followingv results on analysis:

Calculated for (FC4H90) t,-cnnc1o)sinun2 11.6%

Conversion of the t-alkoxy chlorosilanes to the corresponding aminosilanes can be efiected, as shown by the examples, by reaction with ammonia in various ways, It thus is, possible to bubble gaseous, ammonia into a solution of the silane, to run the reaction in the cold in liquid ammonia, to operate with excess ammonia in a closed pressure vessel, or to employ other similar technique. Since the t-carbinoxy amino: silanes will react slowly at room temperature with residual t-carbinoxy chlorosilanes, it is ordinarily preferable that excess ammonia be added as rapidly as possible, that the mixture be maintained at a low or moderate temperature, and that the reaction be completed in the least possible time. The resulting t-carbinoxy aminosilanes can be isolated, e. g. by distillation or crystallization or, when desired, can be used directly in solution.

In these reactions, the ammonia removes and replaces the chlorine atoms in the chlorosilane molecule. The procedure for making and the type of reaction involved in making di-tertiarybutoxydianilinosilane is analogous to that for the product just discussed, except that aniline is employed as the reactant with di-tertiary-butoxyderivatives, further derivative products may be produced and are likewise comprehended.

Where the compounds di-tertiary-butoxydichlorosilane or tri-tert-butoxychlorosilane are shown as intermediates in the preparation of the aminosilanes of this invention, there are also comprehended compounds which contain unlike carbinoxy radicals such as n-butoi:y'-tcr'tiary butoxydichlorosilane, tertiary-butoxytertiaryamoxy-dichlorosilane, tertiary-butoxy-tertiaryamoxy-tertiary-dichlorobutoxychlorosilane, etc. The products obtained on ammonolysis or amina tion of the last-mentioned compounds, or in general of tertiary-carbinoxy chlorosilanes in which the t-carbinoxy group or groups are partially chlorinated, have been found to be particularly stable against hydrolysis of the tertiary-car ,binoxy group. Other products obtained on an1- monolysis or amination of the respective corresponding chlorosilanes include ell-tertiarybutoxydianilinosilane, tertiaryebutoxyphenoxydiaminosilane, and methoxyrt-butoxydiamino=- silane.

Also we have made tertiarywbutoxyoctadecoxydichlorosilane. Upon ammonolysis of this product, there results an organic silicon product containing hydrolyzable nitrogen as well astertiary-butoxy and octadecoxy groups, which prodauctis useful for many of the same purposes as (ii-tertiary-butoxydiaminosilane.

Additional intermediate proclucts compre- 10 handed herein, for further reaction with an monia or the like in the production of the class of compounds contemplated in the present invention are those derived by reaction of silicon oxychloride with tertiary alcohols in the presence of an acid acceptor, e. g. pyridine. (However alpha picoline has been found to have advantages over pyridine in commercial scale operations.) Silicon oxychloride, SizOCls, which mayoccur during the formation ofisilicon tetrachloride, undergoes the same general type of reactions as the latter. For example, by reaction of; this material with tert-butyl alcohol in proper molecular amounts, a number of new intermediates may be prepared, such as sym-tetra -tert;butoxydichlorosiloxane, di-tertbutoxytetrachlorosiloxane and penta-tert-butoxychlorosiloxane. Such compounds may be used as intermediates and converted into amino compounds, e. g. byreace tion with liquid ammonia. For example, the following product has thus been prepared; tetratert-butoxydiaminodisiloxane, B. P. 134-136? C. at 13 mm, n 1.4165, 7.00% nitrogen (calculated for (C4H9O)2Si(NI-I2)OS1(NH2)(OCH-1:02, N 7.0'7 Di-tert butoxytetraminodisiloxane, prepared by aminolysis of di-tert-butoxytetra chlorodisiloxane (C4H9O)2S i2C14O, decomposes, with some resinification, on heating or prolonged standing at room temperatures.

Analogous derivatives of hexachlorodisilane, SizCls, are also contemplated.

Compounds which distinguish over the prior art in a manner parallel to or analogous to the distinctions possessed by the silicon compounds hereinabove illustrated, but which contain an element of groups II I to V of the periodic table other than silicon, for example boron, titanium, phosphorous, etc., are likewise contemplated. Di-t-butoxy titanium diamine is an example of such compounds.

The groups attached to the carbinol carbon of the tertiary-carbinoxy, group may, as hereinbefore indicated, be aliphatic or aromatic; if aliphatic, they may be saturated or unsaturated, and if cyclic, they can contain a hetero atom such as oxygen in the furan ring or sulfur in the thiophene ring. They can be substituted by additional groups which are unreactive toward silicon tetrachloride, such as the halogen, nitro, alkoxy, or acetoxy groups. If aromatic, they can also be substituted with additional groups unreactive toward silicon tetrachloride such as alkylor any of the groups described above.

In the preparation of the aminosilanes, it is important to note that in many cases purification of the tert-carbinoxy chlorosilane intermediate is notnecessary and that the derivative may be made directly, often even in the same reaction vessel, with the crudetert-carbinoxy chlorosilane. However, the use of a tert-carbinQXy chlorQSilane which has been previously purified, as by distillation, is preferred in many cases.

The novel aminosilanes of this invention may be converted directly or indirectly to other forms where desired. For example, the soft resinous material obtainable by ammonolysis of t butoxy trichlorosilane (Example V) may readily be converted to a hard or even brittle resin, substantially insoluble in hydrocarbons; by moderate e n a n ion c on i ap rently responsible for this change, since ammonia is fA mere change in nomenclature from divtert-buto'xjytetrachlorosiloxane, i

liberated during the process. Again, the material obtained on ammonolysis of di-tamoxydichlorosilane (Example Il) may be hydrolyzed by Water, and the product separated and heated to produce a resinous material which, depending on the degree of heating, may vary from a viscous oil through a soft tacky resin to a hard and brittle resin which may be either fusible or infusible. These various resinous products are insoluble in water. They may be used as plasticizing agents, as'ingredients in extreme pressure lubricants, and in waxes and polishes. They are also useful as waterproof coating materials or ingredients thereof, and as ingredients in adhesives, paints and lacquers.

' Among the most important of the characteristics of the aminosilanes of this invention are those which, as have been hereinbefore noted, include (a) the presence of hydrolyzable nitrogen, (b) the resistance to hydrolysis of an organic group or groups, as is the case when 1 to 3 tertiary alkoxy groups are present, (0) the absence (or lack of formation) of corrosive or degradative reaction products on application of the compound to cloth, paper and other acid-sensitive materials and (d) the ability of the compound to provide Water-repellent and generally organophilic properties when applied to such materials, the resulting treated product being capabl of effectively withstanding washing with water or hydrocarbon solvents. These characteristics render the aminosilanes of this invention particularly useful in the treatment of numerous and varied materials and substances. Another important characteristic or property of these aminosilanes, particularly with' respect to the preparation and availability of the compounds themselves, is the stability of the amino or other corresponding nitrogen groups in the presence of at least one tertiary-carbinoxy group. Thus, compounds such as di-t-butoxydiaminosilane are found to be quite resistant to decomposition over extended periods of time, whereas primary carbinoxy diaminosilanes and alkyl diaminosilanes are un= known, presumably because if they were formed, they would be'so unstable that they would immediately decompose.

The new products obtained by the treatment of materials such as cloth and paper with the new compounds of this invention, and the methods of making such products, are described and claimed in the copending application of one of us, Ser. No. 663,947, filed concurrently herewith.

Hereinabove we have illustrated Various specific novel products of our invention and-suitable specific methods for producing the same. It will be understood that variations from these procedures are contemplated and likewise variations in the substituent groups of the products, within the scope of the invention as illustrated herein, are

contemplated. It will also be apparent from the foregoing description that highly important compounds of this invention are the tertiary alkoxy aminosilanes, of which di-tertiary-butoxydiaminosilane and di-tertiary-amoxydiaminosilane have heretofore been given as important examples. Prior'to the time of our original invention, as described in our aforesaid parent application Ser. No. 470,904, to the best of our knowledge no one had ever produced tertiary alkoxy silanes, or other tertiary-carbinoxy silanes as herein described. On the other hand, going back many years, prior workers in the art have, at least on a laboratory scale, produced a number of compounds having primary alkoxy groups at- 12 tached to silicon; and ethyl orthosilicate "has been produced commercially for a great many years. The large amount of prior art work on primary alkoxy silanes, the lesser 'amount of prior art work on secondary alkoxy silanes and the absence of any prior artwork on tertiary alkoxy silanes, or on any 'tertiary-carbinoxy' silanes which appear in any way to simulate or" suggest the products of this invention, is significant in understanding the contribution of this invention. In this general connection, the differences in the chemistry of primary alcohols, secondary alcohols and tertiary alcohols are well known. Further, it is Well known that the normal starting materialin making silanes is silicon. tetrachloride; also that I-ICl is a natural byproduct in making silanes of the type in question. Primary alcohols react only very slowly with HCl;. secondary alcohols react more rapidly than the: primary alcohols but still rather slowly with HCl, while tertiary alcohols react rapidly with H01, vastly more rapidly than the primary alcohols: and much more rapidly than the secondary alcohols: See Organic Chemistry by Fuson and: Snyder, published by John Wiley 8: Sons, New York, 1942, page 51, where comparative times of reactions between H01 and normal butyl alcohol, secondary butyl alcohol and tertiary butyl alcohol, respectively, are shown to be several hours, ten minutes andone minute respectively.

In View of this large difference in behavior of tertiary alcohols such as tertiary butyl alcohol, as compared with primary alcohols, for example, it is apparent that the use of tertiary alcohols, instead of primary alcohols, in various reactions. would present marked differences and problems, from the commercial viewpoint.

This situation is exemplified by the well-knownv fact that while compounds such as primary and secondary butyl acetates have long been avail able commercially at a reasonable cost, tert butyl acetate has not been available commercially, being too expensive and difficult to make and having no apparent advantage over the primary or secondary butyl acetates. Analogously others. may have assumed that, even if they could suc=- ceed in satisfactorily making such compounds as. tertiary-alkoxy chlorosilanes, still there would be no reason to do so, because of (l) the presumably greater difficulty and expense involved in making the same, and (2) the lack of expectation of superior properties of such tertiary-alkoxy silanes, or of new and different characteristics and usefulness thereof. Specifically, we have found no. indication, and have no knowledge, that anyone prior to our invention ever-foresaw that tertiaryalkoxy silanes, as herein illustrated, should be ex-:

pected to have a stability so different from and superior to that of previously known alkoxy silanes (which were mostly primary alkoxy silanes and to a lesser extent, secondary alkoxy silanes). These differences have already been illustrated hereinabove but, as a further illustra-- tion, a dialkoxy dichlorosilane can be converted by aminolysis to the corresponding dialkoxy diaminosilane where at least one alkoxy group is a tertiary alkoxy group but not if both alkoxy groups are primary alkoXy groups. This is of outstanding significance in producing the preferred tertiary carbinoxy amino silanes, and related compounds, particularly described and claimed herein.

The foregoing is meant simply to illustrate and clarify, and not to limit our invention, except as required by the state of the art. 0111' tertiary alkoxy amino silanes, and related organic compounds of silicon, have various novel and unique properties and characteristics which widely distinguish them from prior art organic compounds of silicon, such as their use in making treated or water-repellent fibrous or sheet materials, as hereinabove disclosed, and it is intended herein fully to cover our contributions, without limitation by examples or illustrations given herein.

What we claim is:

1. An organic compound of silicon having both hydrolyzable nitrogen groups and relatively nonhydrolyzable carbin-oxy groups attached to silicon, each hydrolyzable nitrogen group on hydrolysis thereof forming a non-acidic reaction product.

2. A tertiary-carbinoxy silicon compound having both tertiary-carbinoxy and hydrolyzable nitrogen groups attached to silicon.

3. A tertiary-alkoxy silicon compound having both amino and tertiary-alkoxy groups attached to silicon.

. A tertiary-carbinoxy aminosilane.

. A tertiary-alkoxy aminosilane.

. A di-tertiary-carbinoxy diaminosilane. A di-tertiary-alkoxy diaminosilane.

. Di-tertiary-butoxydiaminosilane.

. Di-tertiary-amoxydiaminosilane.

10. Chemical compounds having the molecular formula where R represents a monovalent tertiary organic radical, X represents a monovalent amino group and a: is an integer from 2 to 3.

11. Organic compounds of silicon having the molecular formula where R represents monovalent organic radicals,

at least one RO- group being a tertiary-carbinoxy group, X represents a monovalent amino group and .r is an integer from 2 to 3.

12. Organic compounds of silicon having the molecular formula XI R0-iii-X 14 where R0 is a tertiary-carbinoxy group, X is a monovalent hydrolyzable nitrogen group, and X and X are monovalent groups, each hydrolyzable nitrogen group on hydrolysis thereof formin a non-acidic reaction product.

13. A tertiary-carbinoxy silicon compound containing two amino groups and two carbinoxy groups, all attached to silicon, at least one of said carbinoxy groups being a chlorinated-tertiaryalkoxy group.

14. A tertiary-carbinoxy silicon compound containing, attached to silicon, at least one tertiarycarbinoxy group and at least one readily hydrolyzable group from the class consisting of hydrolyzable nitrogen groups and short-chain primary alkoxy radicals, each said readily hydrolyzable group on hydrolysis thereof forming a non-acidic reaction product.

15. A tertiary-carbinoxy silicon compound containing, attached to silicon, at least one chlorinated-tertiary-carbinoxy group and at least one readily hydrolyzable nitrogen group, each said readily hydrolyzable nitrogen group on hydrolysis thereof forming a non-acidic reaction product.

GEORGE WESLEY PEDLOW, JR. CARL SHELLEY MINER, JR.

REFERENCES CITED The following; references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,053,474 Graves et al. Sept. 8, 1936 2,265,962 Bent et a1. Dec. 9, 1941 2,382,082 McGregn et a1. Aug. 14, 1945 2,386,452 Fleming Oct. 9, 1945 2,389,802 McGregn et al. N... Nov. 27, 1945 2,429,883 Johanson Oct. 28, 1947 OTHER. REFERENCES Kipping et al., J. Chem. Soc., (London) '79 (1901) pages 449-459.

Feiser, Organic Chemistry, 1944, page 32.

Science News Letter, March 22, 193'7, page 188. 

1. AN ORGANIC COMPOUND OF SILICON HAVING BOTH HYDROLYZABLE NITROGEN GROUPS AND RELATIVELY NONHYDROLYZABLE CARBINOXY GROUPS ATTACHED TO SILICON, EACH HYDROLYZABLE NITROGEN GROUP ON HYDROLYSIS THEREOF FORMING A NON-ACIDIC REACTION PRODUCT. 